The head of Russia’s telecommunications regulator says the social networking entrepreneur Pavel Durov’s Telegram Messenger app has provided all the data required to be registered as an information distributor in Russia.

Roskomnadzor chief Aleksandr Zharov made the announcement on June 28, five days after the state regulator threatened to block Telegram for failing to hand over data and secrets about its encrypted-messaging service.

Durov said in a statement that Telegram will “not comply with unconstitutional and technically impossible” requirements of Russian antiterrorism laws that call for access to the correspondence of users.

Telegram promotes itself as an encrypted messaging and content-sharing tool for smartphones and computers that allows free international communication with a “secret chat” feature that promises extra protection against eavesdroppers.

Some governments have said Durov's encrypted-messaging app is used by terrorist organizations to conduct operations in secret.

Durov publicly defied the Russian government’s earlier demands to hand over secret information and data, saying the blocking of his app by the Kremlin would only force private conversations by Russian officials and others to be conducted over U.S.-controlled apps.

Telegram, which is mainly a chat app, has become the most popular social media tool in Iran.